Index: llvm/utils/gn/secondary/BUILD.gn
===================================================================
--- llvm/utils/gn/secondary/BUILD.gn
+++ llvm/utils/gn/secondary/BUILD.gn
@@ -1,9 +1,7 @@
 group("default") {
   deps = [
-    "//llvm/lib/CodeGen",
-    "//llvm/lib/Object",
+    "//llvm/tools/llc",
     "//llvm/tools/llvm-undname",
-    "//llvm/utils/TableGen:llvm-tblgen",
   ]
 }
 
Index: llvm/utils/gn/secondary/llvm/lib/Target/BUILD.gn
===================================================================
--- llvm/utils/gn/secondary/llvm/lib/Target/BUILD.gn
+++ llvm/utils/gn/secondary/llvm/lib/Target/BUILD.gn
@@ -1,5 +1,23 @@
 import("//llvm/lib/Target/targets.gni")
 
+# This build file has two parts:
+# 1. The actual //llvm/lib/Target build target, which is just a static
+#    library containing the cpp files in this directory.  It contains general
+#    shared target code.
+# 2. Forwarding targets that forward to the concrete targets (X86, ARM, ...).
+#    These are defined in subdirectories, and the forwarding names match
+#    the names of the forwarding targets in CMake.  They all (indirectly,
+#    through CodeGen) depend on the //llvm/lib/Target build target.
+# (See also `gn help labels`).
+# The dependency chain is:
+# //llvm/lib/Target:TargetsToBuild (a target in this file) ->
+# /llvm/lib/Target/(X86|ARM|...) (in the subdirectories) ->
+# //llvm/lib/CodeGen ->
+# //llvm/lib/Target (a target in this file again)
+# Note that while this file appears twice in that stack, it's with different
+# targets in this file, so there's no cyclic dependency.
+
+# 1. Actual build target.
 static_library("Target") {
   output_name = "LLVMTarget"
   deps = [
@@ -24,3 +42,49 @@
     "TargetMachineC.cpp",
   ]
 }
+
+# 2. Forwarding targets.
+group("NativeTarget") {
+  deps = [
+    "$native_target",
+  ]
+}
+
+group("TargetsToBuild") {
+  deps = llvm_targets_to_build
+}
+
+group("AllTargetsAsmParsers") {
+  deps = []
+  foreach(target, llvm_targets_to_build) {
+    deps += [ "$target/AsmParser" ]
+  }
+}
+
+group("AllTargetsAsmPrinters") {
+  deps = []
+  foreach(target, llvm_targets_to_build) {
+    deps += [ "$target/InstPrinter" ]
+  }
+}
+
+group("AllTargetsDescs") {
+  deps = []
+  foreach(target, llvm_targets_to_build) {
+    deps += [ "$target/MCTargetDesc" ]
+  }
+}
+
+group("AllTargetsDisassemblers") {
+  deps = []
+  foreach(target, llvm_targets_to_build) {
+    deps += [ "$target/Disassembler" ]
+  }
+}
+
+group("AllTargetsInfos") {
+  deps = []
+  foreach(target, llvm_targets_to_build) {
+    deps += [ "$target/TargetInfo" ]
+  }
+}
Index: llvm/utils/gn/secondary/llvm/lib/Target/X86/AsmParser/BUILD.gn
===================================================================
--- /dev/null
+++ llvm/utils/gn/secondary/llvm/lib/Target/X86/AsmParser/BUILD.gn
@@ -0,0 +1,25 @@
+import("//llvm/utils/TableGen/tablegen.gni")
+
+tablegen("X86GenAsmMatcher") {
+  visibility = [ ":AsmParser" ]
+  args = [ "-gen-asm-matcher" ]
+  td_file = "../X86.td"
+}
+
+static_library("AsmParser") {
+  output_name = "LLVMX86AsmParser"
+  deps = [
+    ":X86GenAsmMatcher",
+    "//llvm/lib/MC",
+    "//llvm/lib/MC/MCParser",
+    "//llvm/lib/Support",
+    "//llvm/lib/Target/X86/InstPrinter",
+    "//llvm/lib/Target/X86/MCTargetDesc",
+    "//llvm/lib/Target/X86/TargetInfo",
+  ]
+  include_dirs = [ ".." ]
+  sources = [
+    "X86AsmInstrumentation.cpp",
+    "X86AsmParser.cpp",
+  ]
+}
Index: llvm/utils/gn/secondary/llvm/lib/Target/X86/BUILD.gn
===================================================================
--- /dev/null
+++ llvm/utils/gn/secondary/llvm/lib/Target/X86/BUILD.gn
@@ -0,0 +1,145 @@
+import("//llvm/utils/TableGen/tablegen.gni")
+
+declare_args() {
+  # Buggy, only use if you know what you're doing.
+  x86_gen_fold_tables = false
+}
+
+tablegen("X86GenCallingConv") {
+  visibility = [ ":LLVMX86CodeGen" ]
+  args = [ "-gen-callingconv" ]
+  td_file = "X86.td"
+}
+
+tablegen("X86GenDAGISel") {
+  visibility = [ ":LLVMX86CodeGen" ]
+  args = [ "-gen-dag-isel" ]
+  td_file = "X86.td"
+}
+
+tablegen("X86GenEVEX2VEXTables") {
+  visibility = [ ":LLVMX86CodeGen" ]
+  args = [ "-gen-x86-EVEX2VEX-tables" ]
+  td_file = "X86.td"
+}
+
+tablegen("X86GenFastISel") {
+  visibility = [ ":LLVMX86CodeGen" ]
+  args = [ "-gen-fast-isel" ]
+  td_file = "X86.td"
+}
+
+tablegen("X86GenGlobalISel") {
+  visibility = [ ":LLVMX86CodeGen" ]
+  args = [ "-gen-global-isel" ]
+  td_file = "X86.td"
+}
+
+tablegen("X86GenRegisterBank") {
+  visibility = [ ":LLVMX86CodeGen" ]
+  args = [ "-gen-register-bank" ]
+  td_file = "X86.td"
+}
+
+if (x86_gen_fold_tables) {
+  tablegen("X86GenFoldTables") {
+    visibility = [ ":LLVMX86CodeGen" ]
+    args = [ "-gen-x86-fold-tables" ]
+    td_file = "X86.td"
+  }
+}
+
+static_library("LLVMX86CodeGen") {
+  deps = [
+    ":X86GenCallingConv",
+    ":X86GenDAGISel",
+    ":X86GenEVEX2VEXTables",
+    ":X86GenFastISel",
+    ":X86GenGlobalISel",
+    ":X86GenRegisterBank",
+    "InstPrinter",
+    "MCTargetDesc",
+    "TargetInfo",
+    "Utils",
+    "//llvm/include/llvm/Config:llvm-config",
+    "//llvm/lib/Analysis",
+    "//llvm/lib/CodeGen",
+    "//llvm/lib/CodeGen/AsmPrinter",
+    "//llvm/lib/CodeGen/GlobalISel",
+    "//llvm/lib/CodeGen/SelectionDAG",
+    "//llvm/lib/IR",
+    "//llvm/lib/MC",
+    "//llvm/lib/Support",
+    "//llvm/lib/Target",
+  ]
+  if (x86_gen_fold_tables) {
+    deps += [ ":X86GenFoldTables" ]
+  }
+  sources = [
+    "ShadowCallStack.cpp",
+    "X86AsmPrinter.cpp",
+    "X86AvoidStoreForwardingBlocks.cpp",
+    "X86CallFrameOptimization.cpp",
+    "X86CallLowering.cpp",
+    "X86CallingConv.cpp",
+    "X86CmovConversion.cpp",
+    "X86CondBrFolding.cpp",
+    "X86DiscriminateMemOps.cpp",
+    "X86DomainReassignment.cpp",
+    "X86EvexToVex.cpp",
+    "X86ExpandPseudo.cpp",
+    "X86FastISel.cpp",
+    "X86FixupBWInsts.cpp",
+    "X86FixupLEAs.cpp",
+    "X86FixupSetCC.cpp",
+    "X86FlagsCopyLowering.cpp",
+    "X86FloatingPoint.cpp",
+    "X86FrameLowering.cpp",
+    "X86ISelDAGToDAG.cpp",
+    "X86ISelLowering.cpp",
+    "X86IndirectBranchTracking.cpp",
+    "X86InsertPrefetch.cpp",
+    "X86InstrFMA3Info.cpp",
+    "X86InstrFoldTables.cpp",
+    "X86InstrInfo.cpp",
+    "X86InstructionSelector.cpp",
+    "X86InterleavedAccess.cpp",
+    "X86LegalizerInfo.cpp",
+    "X86MCInstLower.cpp",
+    "X86MachineFunctionInfo.cpp",
+    "X86MacroFusion.cpp",
+    "X86OptimizeLEAs.cpp",
+    "X86PadShortFunction.cpp",
+    "X86RegisterBankInfo.cpp",
+    "X86RegisterInfo.cpp",
+    "X86RetpolineThunks.cpp",
+    "X86SelectionDAGInfo.cpp",
+    "X86ShuffleDecodeConstantPool.cpp",
+    "X86SpeculativeLoadHardening.cpp",
+    "X86Subtarget.cpp",
+    "X86TargetMachine.cpp",
+    "X86TargetObjectFile.cpp",
+    "X86TargetTransformInfo.cpp",
+    "X86VZeroUpper.cpp",
+    "X86WinAllocaExpander.cpp",
+    "X86WinEHState.cpp",
+  ]
+}
+
+# This is a bit different from most build files: Due to this group
+# having the directory's name, "//llvm/lib/Target/X86" will refer to this
+# target, which pulls in the code in this directory *and all subdirectories*.
+# For most other directories, "//llvm/lib/Foo" only pulls in the code directly
+# in "llvm/lib/Foo". The forwarding targets in //llvm/lib/Target expect this
+# different behavior.
+group("X86") {
+  deps = [
+    ":LLVMX86CodeGen",
+    "AsmParser",
+    "Disassembler",
+    "InstPrinter",
+    "MCTargetDesc",
+    "TargetInfo",
+    "Utils",
+  ]
+}
Index: llvm/utils/gn/secondary/llvm/lib/Target/X86/Disassembler/BUILD.gn
===================================================================
--- /dev/null
+++ llvm/utils/gn/secondary/llvm/lib/Target/X86/Disassembler/BUILD.gn
@@ -0,0 +1,23 @@
+import("//llvm/utils/TableGen/tablegen.gni")
+
+tablegen("X86GenDisassemblerTables") {
+  visibility = [ ":Disassembler" ]
+  args = [ "-gen-disassembler" ]
+  td_file = "../X86.td"
+}
+
+static_library("Disassembler") {
+  output_name = "LLVMX86Disassembler"
+  deps = [
+    ":X86GenDisassemblerTables",
+    "//llvm/lib/MC/MCDisassembler",
+    "//llvm/lib/Support",
+    "//llvm/lib/Target/X86/MCTargetDesc",
+    "//llvm/lib/Target/X86/TargetInfo",
+  ]
+  include_dirs = [ ".." ]
+  sources = [
+    "X86Disassembler.cpp",
+    "X86DisassemblerDecoder.cpp",
+  ]
+}
Index: llvm/utils/gn/secondary/llvm/lib/Target/X86/InstPrinter/BUILD.gn
===================================================================
--- /dev/null
+++ llvm/utils/gn/secondary/llvm/lib/Target/X86/InstPrinter/BUILD.gn
@@ -0,0 +1,38 @@
+import("//llvm/utils/TableGen/tablegen.gni")
+
+tablegen("X86GenAsmWriter") {
+  visibility = [ ":InstPrinter" ]
+  args = [ "-gen-asm-writer" ]
+  td_file = "../X86.td"
+}
+
+tablegen("X86GenAsmWriter1") {
+  visibility = [ ":InstPrinter" ]
+  args = [
+    "-gen-asm-writer",
+    "-asmwriternum=1",
+  ]
+  td_file = "../X86.td"
+}
+
+static_library("InstPrinter") {
+  output_name = "LLVMX86AsmPrinter"
+  deps = [
+    ":X86GenAsmWriter",
+    ":X86GenAsmWriter1",
+    "//llvm/lib/MC",
+    "//llvm/lib/Support",
+
+    # MCTargetDesc depends on InstPrinter, so we can't depend on the full
+    # MCTargetDesc target here: it would form a cycle.
+    "//llvm/lib/Target/X86/MCTargetDesc:tablegen",
+    "//llvm/lib/Target/X86/Utils",
+  ]
+  include_dirs = [ ".." ]
+  sources = [
+    "X86ATTInstPrinter.cpp",
+    "X86InstComments.cpp",
+    "X86InstPrinterCommon.cpp",
+    "X86IntelInstPrinter.cpp",
+  ]
+}
Index: llvm/utils/gn/secondary/llvm/lib/Target/X86/MCTargetDesc/BUILD.gn
===================================================================
--- /dev/null
+++ llvm/utils/gn/secondary/llvm/lib/Target/X86/MCTargetDesc/BUILD.gn
@@ -0,0 +1,59 @@
+import("//llvm/utils/TableGen/tablegen.gni")
+
+tablegen("X86GenInstrInfo") {
+  visibility = [ ":tablegen" ]
+  args = [ "-gen-instr-info" ]
+  td_file = "../X86.td"
+}
+
+tablegen("X86GenRegisterInfo") {
+  visibility = [ ":tablegen" ]
+  args = [ "-gen-register-info" ]
+  td_file = "../X86.td"
+}
+
+tablegen("X86GenSubtargetInfo") {
+  visibility = [ ":tablegen" ]
+  args = [ "-gen-subtarget" ]
+  td_file = "../X86.td"
+}
+
+group("tablegen") {
+  visibility = [
+    ":MCTargetDesc",
+    "../InstPrinter",
+    "../TargetInfo",
+  ]
+  public_deps = [
+    ":X86GenInstrInfo",
+    ":X86GenRegisterInfo",
+    ":X86GenSubtargetInfo",
+  ]
+}
+
+static_library("MCTargetDesc") {
+  output_name = "LLVMX86Desc"
+  public_deps = [
+    ":tablegen",
+  ]
+  deps = [
+    "//llvm/lib/MC",
+    "//llvm/lib/MC/MCDisassembler",
+    "//llvm/lib/Object",
+    "//llvm/lib/Support",
+    "//llvm/lib/Target/X86/InstPrinter",
+    "//llvm/lib/Target/X86/TargetInfo",
+  ]
+  include_dirs = [ ".." ]
+  sources = [
+    "X86AsmBackend.cpp",
+    "X86ELFObjectWriter.cpp",
+    "X86MCAsmInfo.cpp",
+    "X86MCCodeEmitter.cpp",
+    "X86MCTargetDesc.cpp",
+    "X86MachObjectWriter.cpp",
+    "X86WinCOFFObjectWriter.cpp",
+    "X86WinCOFFStreamer.cpp",
+    "X86WinCOFFTargetStreamer.cpp",
+  ]
+}
Index: llvm/utils/gn/secondary/llvm/lib/Target/X86/TargetInfo/BUILD.gn
===================================================================
--- /dev/null
+++ llvm/utils/gn/secondary/llvm/lib/Target/X86/TargetInfo/BUILD.gn
@@ -0,0 +1,14 @@
+static_library("TargetInfo") {
+  output_name = "LLVMX86Info"
+  deps = [
+    "//llvm/lib/Support",
+
+    # MCTargetDesc depends on TargetInfo, so we can't depend on the full
+    # MCTargetDesc target here: it would form a cycle.
+    "//llvm/lib/Target/X86/MCTargetDesc:tablegen",
+  ]
+  include_dirs = [ ".." ]
+  sources = [
+    "X86TargetInfo.cpp",
+  ]
+}
Index: llvm/utils/gn/secondary/llvm/lib/Target/X86/Utils/BUILD.gn
===================================================================
--- /dev/null
+++ llvm/utils/gn/secondary/llvm/lib/Target/X86/Utils/BUILD.gn
@@ -0,0 +1,9 @@
+static_library("Utils") {
+  output_name = "LLVMX86Utils"
+  deps = [
+    "//llvm/lib/Support",
+  ]
+  sources = [
+    "X86ShuffleDecode.cpp",
+  ]
+}
Index: llvm/utils/gn/secondary/llvm/lib/Target/targets.gni
===================================================================
--- llvm/utils/gn/secondary/llvm/lib/Target/targets.gni
+++ llvm/utils/gn/secondary/llvm/lib/Target/targets.gni
@@ -8,18 +8,18 @@
 if (llvm_targets_to_build == "host") {
   if (host_cpu == "x86" || host_cpu == "x64") {
     llvm_targets_to_build = [ "X86" ]
-  } else if (host_cpu == "arm") {
-    llvm_targets_to_build = [ "ARM" ]
-  } else if (host_cpu == "arm64") {
-    llvm_targets_to_build = [ "AArch64" ]
+    #} else if (host_cpu == "arm") {
+    #llvm_targets_to_build = [ "ARM" ]
+    #} else if (host_cpu == "arm64") {
+    #llvm_targets_to_build = [ "AArch64" ]
   } else {
     assert(false, "add your host_cpu above")
   }
 } else if (llvm_targets_to_build == "all") {
   # FIXME: Port the remaining targets.
   llvm_targets_to_build = [
-    "AArch64",
-    "ARM",
+    #"AArch64",
+    #"ARM",
     "X86",
   ]
 }
@@ -45,10 +45,10 @@
 # FIXME: This should be based off target_cpu once cross compiles work.
 if (host_cpu == "x86" || host_cpu == "x64") {
   native_target = "X86"
-} else if (host_cpu == "arm") {
-  native_target = "ARM"
-} else if (host_cpu == "arm64") {
-  native_target = "AArch64"
+  #} else if (host_cpu == "arm") {
+  #native_target = "ARM"
+  #} else if (host_cpu == "arm64") {
+  #native_target = "AArch64"
 } else {
   assert(false, "Unsuppored host_cpu '$host_cpu'.")
 }
Index: llvm/utils/gn/secondary/llvm/tools/llc/BUILD.gn
===================================================================
--- /dev/null
+++ llvm/utils/gn/secondary/llvm/tools/llc/BUILD.gn
@@ -0,0 +1,28 @@
+executable("llc") {
+  deps = [
+    "//llvm/lib/Analysis",
+    "//llvm/lib/CodeGen",
+    "//llvm/lib/CodeGen/AsmPrinter",
+    "//llvm/lib/CodeGen/MIRParser",
+    "//llvm/lib/CodeGen/SelectionDAG",
+    "//llvm/lib/IR",
+    "//llvm/lib/IRReader",
+    "//llvm/lib/MC",
+    "//llvm/lib/Support",
+    "//llvm/lib/Target",
+    "//llvm/lib/Target:TargetsToBuild",
+    "//llvm/lib/Transforms/Scalar",
+    "//llvm/lib/Transforms/Utils",
+    "//llvm/lib/Transforms/Vectorize",
+  ]
+  sources = [
+    "llc.cpp",
+  ]
+
+  # Support plugins.
+  # FIXME: Disable dead stripping once other binaries are dead-stripped
+  if (host_os == "linux") {
+    # Corresponds to export_executable_symbols() in cmake.
+    ldflags = [ "-rdynamic" ]
+  }
+}